A Science of Operations: Machines, Logic and the Invention of Processing

344 Pages·2010·1.942 MB·English

by  Priestley, Mark

History of Computing
SeriesEditor
MartinCampbell-Kelly,UniversityofWarwick,Coventry,UK
AdvisoryBoard
GerardAlberts,UniversityofAmsterdam,Amsterdam,TheNetherlands
JackCopeland,UniversityofCanterbury,Christchurch,NewZealand
UlfHashagen,DeutschesMuseum,Munich,Germany
JohnV.Tucker,SwanseaUniversity,Swansea,UK
JeffreyR.Yost,UniversityofMinnesota,Minneapolis,USA
TheHistoryofComputingseriespublisheshigh-qualitybookswhichaddressthehistoryofcomputing,
withanemphasis onthe‘externalist’ viewofthis history, more accessibletoawideraudience.The
seriesexaminescontentandhistoryfromfourmainquadrants:thehistoryofrelevanttechnologies,the
historyofthecorescience,thehistoryofrelevantbusinessandeconomicdevelopments,andthehistory
ofcomputingasitpertainstosocialhistoryandsocietaldevelopments.
Titlescanspanavarietyofproducttypes,includingbutnotexclusively,themedvolumes,biographies,
‘profile’books(withbriefbiographiesofanumberofkeypeople),expansionsofworkshopproceedings,
generalreaders,scholarlyexpositions,titlesusedasancillarytextbooks,revivalsandneweditionsof
previousworthytitles.
Thesebookswillappeal,varyingly,toacademicsandstudentsincomputerscience,history,mathematics,
businessandtechnologystudies.Sometitleswillalsodirectlyappealtoprofessionalsandpractitioners
ofdifferentbackgrounds.
Authorguidelines:springer.com>Authors>AuthorGuidelines
Forothertitlespublishedinthisseries,gotowww.springer.com/series/8442
Mark Priestley
A Science
of Operations
Machines, Logic and the Invention
of Programming
Dr.MarkPriestley
London
UK
[email protected]
url:http://www.markpriestley.net
ISSN2190-6831 e-ISSN2190-684X
ISBN978-1-84882-554-3 e-ISBN978-1-84882-555-0
DOI10.1007/978-1-84882-555-0
SpringerLondonDordrechtHeidelbergNewYork
BritishLibraryCataloguinginPublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary
LibraryofCongressControlNumber:2011921403
©Springer-VerlagLondonLimited2011
Apartfromanyfairdealingforthepurposesofresearchorprivatestudy,orcriticismorreview,asper-
mittedundertheCopyright,DesignsandPatentsAct1988,thispublicationmayonlybereproduced,
storedortransmitted,inanyformorbyanymeans,withthepriorpermissioninwritingofthepublish-
ers,orinthecaseofreprographicreproductioninaccordancewiththetermsoflicensesissuedbythe
CopyrightLicensingAgency.Enquiriesconcerningreproductionoutsidethosetermsshouldbesentto
thepublishers.
Theuseofregisterednames,trademarks,etc.,inthispublicationdoesnotimply,evenintheabsenceofa
specificstatement,thatsuchnamesareexemptfromtherelevantlawsandregulationsandthereforefree
forgeneraluse.
Thepublishermakesnorepresentation,expressorimplied,withregardtotheaccuracyoftheinformation
containedinthisbookandcannotacceptanylegalresponsibilityorliabilityforanyerrorsoromissions
thatmaybemade.
Coverdesign:deblik
Printedonacid-freepaper
SpringerispartofSpringerScience+BusinessMedia(www.springer.com)
Preface
Ithaslongbeenrecognizedthatthereisarelationshipbetweenlogicandcomputer
programming.Sincethe1940smanylogicians,includingAlanTuringandJohnvon
Neumann,andcomputerscientistssuchasEdsgarDijkstraandJohnMcCarthy,have
drawn attention to the connection between the two disciplines and commented on
its importance. During the formal methods boom of the 1980s and 1990s it was
common to read assertions to the effect that programming could be reduced to a
quasi-logicalprocessoftheoremprovingandformuladerivation.
However,despitehavingabackgroundinbothprogrammingandlogic,Ifound
somethingelusiveaboutsuchassertions.Mypracticalexperienceofprogramming
hadledmetounderstanditasaverydifferenttypeofactivityfromtheformalma-
nipulationsoflogicalproof.Withtheintentionofresolvingthisuncertainty,Iem-
barkeduponaPh.D.tostudythewaysinwhichthedevelopmentofprogramming
languageshadbeeninfluencedbylogic.Thisbookisbasedontheresultingthesis,
althoughithasawiderfocusandmarksafurtherstageinmygrowingunderstanding
oftheconnectionbetweenthetwoareas.
Broadlyspeaking,Ihavecometounderstandthisconnectionnotasafactabout
the two disciplines, but as something more like a decision made by identifiable
historicalactorsastohowthenewdisciplineofprogrammingshouldbeunderstood
andstructured.AkeyeventinthisprocesswasthecreationoftheAlgollanguage
in the years around 1960. The motivation for this decision has very deep roots,
however, reaching back to ideas about machines and machinic processes that date
fromtheverybeginningofthescientificrevolution.
From this starting point, the book gives an account of the history of what we
now call programming. It is useful, however, to view this not simply as computer
programming,but to think more generallyof attempts to define the steps involved
incomputationsandotherinformation-processingactivitiesinsuchawaythatthey
could be performed by machines, or at least by humans mimicking the behaviour
of machines. From this perspective, the history of programming is distinct from
the history of the computer, despite the close relationship between the two in the
twentiethcentury.
v
vi Preface
Thestorytoldinthisbookstopsinthe1970s,atthepointwhereobject-oriented
programming emerged as a successor, or alternative, to structured programming.
Thisisnotanarbitrarycut-offpoint;rather,Ibelievethatstructuredprogramming
marksthecompletionofaparticularhistoricaltrajectory,andthatobject-orientation,
despiteitsrichinheritancefromexistingpractices,issomethingquitedifferent,or
at least something which has deep roots in approaches and disciplines other than
logic.Untanglingtheserootsispartofadifferentproject,however,andthehistory
ofhowprogrammingandprogramminglanguagesdevelopedafterthe1970sispart
ofadifferentstoryfromtheonetoldhere.
There are several things this book is not, therefore. Although it contains much
historical material, it does not pretend to be a complete history of programming
languages,andstilllessahistoryofthecomputer.Whatitdoestrytodoistotella
particularstoryaboutthesehistoricaldevelopmentsandtoshowonewayinwhich
thehistoryofprogramminglanguagescanbesetinawidercontextandseenasan
integralpartofadevelopmentwhich,ultimately,iscentraltotheprojectstartedby
thescientificrevolutionintheseventeenthcentury.
The history of computing has recently been expanding its focus from technical
details and embracing wider narratives and historical contexts. These encouraging
developments have been principally evident in studies of commercial and military
applicationsofcomputingandtheirsocietalimpacts.IfIhadasinglehopeforthis
book,itwouldbethatitmightcontributetoasimilarprocessinthemoretechnical
aspectsofthesubjectandtoinspirecomputerscientistsandhistoriansofscienceand
technologytoseeprogrammingnotasaisolatedtechnicalfield.butasaninteresting
andimportantpartofgeneralintellectualhistory.
Acknowledgements I would like particularly to thank my supervisor Donald
GilliesandexternalexaminerJohnTucker,withoutwhoseenthusiasticadvice,sup-
portandencouragementthisbookwouldneverhaveseenthelightofday.
London,UK MarkPriestley
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Minds,MethodandMachines . . . . . . . . . . . . . . . . . . . . 3
1.2 LanguageandScience . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 TheAgeofMachinery . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4 TheMechanizationofMathematicalLanguage . . . . . . . . . . . 8
2 Babbage’sEngines . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1 TheDivisionofMentalLabour . . . . . . . . . . . . . . . . . . . 18
2.2 TheDifferenceEngine . . . . . . . . . . . . . . . . . . . . . . . . 21
2.3 TheMeaningsoftheDifferenceEngine . . . . . . . . . . . . . . . 25
2.4 TheMechanicalNotation . . . . . . . . . . . . . . . . . . . . . . 28
2.5 TheAnalyticalEngine . . . . . . . . . . . . . . . . . . . . . . . . 31
2.6 TheScienceofOperations . . . . . . . . . . . . . . . . . . . . . . 41
2.7 TheMeaningsoftheAnalyticalEngine . . . . . . . . . . . . . . . 44
2.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3 Semi-AutomaticComputing . . . . . . . . . . . . . . . . . . . . . . . 53
3.1 TheCensusProblem . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2 TheHollerithTabulatingSystemof1890 . . . . . . . . . . . . . . 55
3.3 FurtherDevelopmentsinPunchedCardMachines . . . . . . . . . 57
3.4 ComrieandtheMechanizationofScientificCalculation . . . . . . 60
3.5 Semi-AutomaticProgramming . . . . . . . . . . . . . . . . . . . 65
4 Logic,ComputabilityandFormalSystems . . . . . . . . . . . . . . . 67
4.1 Gödel’sConstruction . . . . . . . . . . . . . . . . . . . . . . . . 69
4.2 RecursiveFunctions . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.3 λ-definability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.4 DirectApproachestoDefiningEffectiveComputability . . . . . . 75
4.5 Turing’sMachineTableNotation . . . . . . . . . . . . . . . . . . 77
4.6 UniversalMachines . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.7 TheConceptofaFormalLanguage . . . . . . . . . . . . . . . . . 92
4.8 TheRelationshipBetweenTuring’sWorkandLogic . . . . . . . . 96
vii
viii Contents
5 AutomatingControl . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
5.1 KonradZuse’sEarlyMachines . . . . . . . . . . . . . . . . . . . 100
5.2 MarkI:TheAutomaticSequenceControlledCalculator . . . . . . 102
5.3 TheENIAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
5.4 TheBellLabsRelayMachines . . . . . . . . . . . . . . . . . . . 115
5.5 TheSignificanceoftheAutomaticCalculators . . . . . . . . . . . 118
6 LogicandtheInventionoftheComputer . . . . . . . . . . . . . . . . 123
6.1 TheOriginsoftheStored-ProgramComputer. . . . . . . . . . . . 126
6.2 TheEarlyDevelopmentofCybernetics . . . . . . . . . . . . . . . 130
6.3 VonNeumann’sDesignfortheEDVAC . . . . . . . . . . . . . . . 133
6.4 LogicandtheStored-ProgramConcept . . . . . . . . . . . . . . . 136
6.5 TheEDVACCodeandAddressModification . . . . . . . . . . . . 139
6.6 TuringandtheACE . . . . . . . . . . . . . . . . . . . . . . . . . 142
6.7 GiantBrains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
6.8 UniversalMachines . . . . . . . . . . . . . . . . . . . . . . . . . 147
6.9 General-PurposeMachines . . . . . . . . . . . . . . . . . . . . . 153
6.10 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
7 MachineCodeProgrammingandLogic . . . . . . . . . . . . . . . . 157
7.1 SequencingofOperations . . . . . . . . . . . . . . . . . . . . . . 158
7.2 TransferofControl. . . . . . . . . . . . . . . . . . . . . . . . . . 162
7.3 ConditionTesting . . . . . . . . . . . . . . . . . . . . . . . . . . 164
7.4 InstructionModification . . . . . . . . . . . . . . . . . . . . . . . 167
7.5 Subroutines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
7.6 MachineCodeandProgramStructures . . . . . . . . . . . . . . . 172
7.7 MachineCodeandLogic . . . . . . . . . . . . . . . . . . . . . . 174
7.8 Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
7.9 FlowDiagramsandProgramSemantics . . . . . . . . . . . . . . . 179
7.10 ProgramsasMetalinguisticExpressions . . . . . . . . . . . . . . 182
7.11 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
8 TheInventionofProgrammingLanguages . . . . . . . . . . . . . . . 185
8.1 AutomaticCoding . . . . . . . . . . . . . . . . . . . . . . . . . . 186
8.2 TheSemanticsofPseudocodes . . . . . . . . . . . . . . . . . . . 188
8.3 FormulaTranslation . . . . . . . . . . . . . . . . . . . . . . . . . 193
8.4 FortranandIncreasingLinguisticComplexity . . . . . . . . . . . 197
8.5 UniversalLanguages . . . . . . . . . . . . . . . . . . . . . . . . . 204
8.6 Algol60asaFormalLanguage . . . . . . . . . . . . . . . . . . . 209
8.7 TheInfluenceofLogiconAlgol. . . . . . . . . . . . . . . . . . . 217
8.8 LispandRecursiveFunctionTheory . . . . . . . . . . . . . . . . 220
8.9 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
9 TheAlgolResearchProgramme. . . . . . . . . . . . . . . . . . . . . 225
9.1 Algol60asaConcreteParadigm . . . . . . . . . . . . . . . . . . 226
9.2 NormalScienceintheAlgolResearchProgramme . . . . . . . . . 229
Contents ix
9.3 TheDescriptionofProgrammingLanguages . . . . . . . . . . . . 230
9.4 DifferentPhilosophiesofProgrammingLanguageDesign . . . . . 237
9.5 LogicandtheDesignofControlStructures . . . . . . . . . . . . . 239
9.6 LogicandDataStructures . . . . . . . . . . . . . . . . . . . . . . 244
9.7 ModellingDataforInformationRetrieval . . . . . . . . . . . . . . 247
9.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
10 TheLogicofCorrectnessinSoftwareEngineering . . . . . . . . . . 253
10.1 CheckingComputations . . . . . . . . . . . . . . . . . . . . . . . 253
10.2 DebuggingandTesting . . . . . . . . . . . . . . . . . . . . . . . 255
10.3 CorrectnessProofs . . . . . . . . . . . . . . . . . . . . . . . . . . 257
10.4 ConstructiveMethods . . . . . . . . . . . . . . . . . . . . . . . . 261
10.5 SpecificationsandCorrectness . . . . . . . . . . . . . . . . . . . 263
10.6 StructuredProgramming . . . . . . . . . . . . . . . . . . . . . . . 265
10.7 ProofandTesting . . . . . . . . . . . . . . . . . . . . . . . . . . 269
10.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
11 TheUnificationofDataandAlgorithms . . . . . . . . . . . . . . . . 277
11.1 SimulationLanguages . . . . . . . . . . . . . . . . . . . . . . . . 278
11.2 ModellingtheRealWorld . . . . . . . . . . . . . . . . . . . . . . 281
11.3 Simula67 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
11.4 DataAbstraction . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
11.5 Smalltalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
11.6 TheRelationshipBetweenSmalltalkandLogic. . . . . . . . . . . 293
11.7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
12 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
12.1 ParadigmsandRevolutions . . . . . . . . . . . . . . . . . . . . . 298
12.2 RelatingTheoryandPractice . . . . . . . . . . . . . . . . . . . . 301
12.3 MethodologicalConclusions . . . . . . . . . . . . . . . . . . . . 303
Appendix Turing’sUniversalMachine . . . . . . . . . . . . . . . . . . 307
A.1 GeneralPurposem-functions . . . . . . . . . . . . . . . . . . . . 307
A.2 TheContentsoftheTape . . . . . . . . . . . . . . . . . . . . . . 310
A.3 TheMainTable . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335